<h2>vm_deallocate</h2><hr><p><strong>Function</strong> - Deallocate a region of virtual memory.
<h3>SYNOPSIS</h3><pre><strong>kern_return_t vm_deallocate</strong><strong>(vm_task_t</strong><var>target_task</var>,
<strong>vm_address_t</strong><var>address</var>,
<strong>vm_size_t</strong><var>size</var><strong>);</strong></pre><h3>PARAMETERS</h3><dl><p><dt><var>target_task</var><dd>
[in task send right]
The port for the task in whose address space the
region is to be deallocated.
<p><dt><var>address</var><dd>
[in scalar]
The starting address for the region.
<p><dt><var>size</var><dd>
[in scalar]
The number of bytes to deallocate.
</dl><h3>DESCRIPTION</h3><p>
The <strong>vm_deallocate</strong> function deallocates a region of
virtual memory in the
specified task's address space.
The region starts at the beginning of the virtual page containing
<var>address</var> and ends
at the end of the virtual page containing <var>address</var>
+ <var>size</var> - 1. Because of this
rounding to virtual page boundaries, the amount of memory deallocated may be
greater than <var>size</var>. Use <strong>host_page_size</strong>
to find the current virtual page size.
<p><strong>vm_deallocate</strong> affects only <var>target_task</var>. Other tasks
that have access to the deallocated memory can continue to reference it.
<h3>NOTES</h3><p><strong>vm_deallocate</strong> can be used to deallocate memory passed
as out-of-line data in a
message.
<p>
This interface is machine word length specific because of the virtual address
parameter.
<h3>RETURN VALUES</h3><dl><p><dt><strong>KERN_INVALID_ADDRESS</strong><dd>
The address is illegal or specifies a non-allocated region.
</dl><h3>RELATED INFORMATION</h3><p>
Functions:
<a href="mach_msg.html"><strong>mach_msg</strong></a>,
<a href="vm_allocate.html"><strong>vm_allocate</strong></a>,
<a href="vm_map.html"><strong>vm_map</strong></a>,
<a href="host_page_size.html"><strong>host_page_size</strong></a>.